L-Arginine Metabolism in Essential Hypertension

Inclusion Criteria: * Males, ages 18-65 * Male and female healthy control subjects ages 18-65 Exclusion Criteria: * Any other coexisting condition * Advanced damage of vital organs (grade III und IV retinopathy) * Therapy with a not approved concomitant medication in the last 4 weeks prior to intake of the first trial medication, especially lipid lowering and antidiabetic medications (washout phase) * Blood donation within the last 4 weeks * Patients with arterial fibrillation or atrioventricular (AV)-block (II and more) * Patients with anamnestic myocardial infarct * Patients with depression * Patients with seizure disorders * Patients with unstable angina pectoris including electrocardiogram (ECG)-aberrations or cardiac insufficiency New York Heart Association (NYHA) Stadium III and IV * History of a malignant illness with the exception of those patients who have recovered for more than 10 years or have a basalioma of the skin. * Actual or anamnestic alcohol or drug abuse * History of organ transplant * Anaphylaxis or known therapy resistance to any of the used test matters. * Therapy with a not approved concomitant therapy * Participation in another study within three months prior to study inclusion * Illnesses, which can influence the pharmacodynamics or pharmacokinetics of the test substance * Liver or kidney diseases: SGOT, GPT , γ-GT, AP, bilirubin and creatinine above 200% of standard * Patients who are not sufficiently compliant; or patients who are not capable or willing to appear for controlling visits. * Severe or unstable medical or psychiatric illnesses, which will, in the estimation of the examiner, endanger the safety of the proband or the successful participation in the study * Presumed risk of transmission of HIV or hepatitis via blood from the proband